[Feature Request] The ability to reset images to unread, without removing favorites

[tuckjohn]

I would like to be able to reset my read comics to be unread, without removing my favorited comics (and cashed images), so that I can enjoy going through all of them again, and favorite any additional comics that I like.

Currently, there is only the "clear cashe" button, which would remove all of my favorites.

Possible solution: add another button (in the same menu that the "clear cashe" button is in) to "Mark all comics as unread"